Condensed cyclic compound and organic light-emitting device including the same

ABSTRACT

A condensed cyclic compound and an organic light-emitting device including the same are provided. The condensed cyclic compound is represented by Formula 1:

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and benefits of Korean PatentApplication No. 10-2019-0152594 under 35 U.S.C. § 119, filed on Nov. 25,2019 in the Korean Intellectual Property Office, the disclosure entirecontents of which are incorporated herein by reference.

BACKGROUND 1. Technical Field

Embodiments relate to a condensed cyclic compound and an organiclight-emitting device including the same.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that producefull-color images, and also have wide viewing angles, high contrastratios, short response times, and excellent characteristics in terms ofbrightness, driving voltage, and response speed, compared to devices inthe art.

An organic light-emitting device may include a first electrode on asubstrate, and a hole transport region, an emission layer, an electrontransport region, and a second electrode, which are sequentiallydisposed on the first electrode. Holes provided from the first electrodemay move toward the emission layer through the hole transport region,and electrons provided from the second electrode may move toward theemission layer through the electron transport region. Carriers, such asholes and electrons, recombine in the emission layer to produceexcitons. These excitons transit from an excited state to a groundstate, thereby generating light.

SUMMARY

Embodiments include a condensed cyclic compound and an organiclight-emitting device including the same.

Additional embodiments will be set forth in part in the descriptionwhich follows and, in part, will be apparent from the description, ormay be learned by practice of the embodiments of the disclosure.

In an embodiment, a condensed cyclic compound is represented by Formula1:

-(L₂₁)_(a21)-(Ar₂₁)_(b21)  <Formula 2>

wherein in Formula 1 and Formula 2,

B is boron,

ring A₁ to ring A₅ may each independently be selected from a benzenering, a naphthalene ring, a pyridine ring, a pyrimidine ring, apyridazine ring, and a pyrazine ring,

Z₁ may be C(R₁) or N, Z₂ may be C(R₂) or N, Z₃ may be C(R₃) or N,

X₁ to X₄ may each independently be selected from C(R₁₁)(R₁₂),Si(R₁₁)(R₁₂), N(R₁₁), O, and S,

L₂₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or asubstituted or unsubstituted C₁-C₆₀ heterocyclic group,

a21 may be an integer from 0 to 3,

Ar₂₁ may be selected from a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substitutedor unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group,a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and —N(R₁₃)(R₁₄),

b21 may be an integer from 1 to 5,

R₁ to R₈ may each independently be selected from a group represented byFormula 2, hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an am idino group, a hydrazine group, ahydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid ora salt thereof, a phosphoric acid or a salt thereof, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and—P(═O)(Q₁)(Q₂),

R₁₁ to R₁₄ may each independently be selected from a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group,

with the proviso that: when at least one of X₁ to X₄ is selected fromC(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), and N(R₁₁), at least one pair of substituentsmay be optionally linked via a single bond or a linking group to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, the pair of substituentsselected from the group consisting of R₁₁ and R₁₂, ring A₁ and R₁₁, ringA₄ and R₁₁, ring A₅ and R₁₁, ring A₆ and R₁₁, and ring A₇ and R₁₁,

c4 to c8 may each independently be an integer from 0 to 6,

at least one substituent of the substituted C₅-C₆₀ carbocyclic group,the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may eachindependently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, aC₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group, and

* indicates a binding site to a neighboring atom.

In an embodiment, an organic light-emitting device may include a firstelectrode, a second electrode facing the first electrode, and an organiclayer disposed between the first electrode and the second electrode andincluding an emission layer, and the organic light-emitting device mayinclude a condensed cyclic compound represented by Formula 1.

In an embodiment, the first electrode may be an anode, the secondelectrode may be a cathode, the organic layer may comprise the condensedcyclic compound, a hole transport region disposed between the firstelectrode and the emission layer, and an electron transport regiondisposed between the emission layer and the second electrode. The holetransport region may comprise a hole injection layer, a hole transportlayer, an emission auxiliary layer, an electron blocking layer, or anycombination thereof. The electron transport region may comprise a bufferlayer, a hole blocking layer, an electron transport layer, an electroninjection layer, or any combination thereof.

In an embodiment, the emission layer may comprise the condensed cycliccompound.

In an embodiment, the condensed cyclic compound included in the emissionlayer may be a thermally activated delayed fluorescence emitter (TADFemitter), and the emission layer may emit delayed fluorescence.

In an embodiment, the emission layer may further comprise a host, thecondensed cyclic compound included in the emission layer may be adopant, and an amount of the host included in the emission layer may begreater than an amount of the condensed cyclic compound included in theemission layer.

In an embodiment, the host may include an anthracene compound, acarbazole compound, a benzimidazole compound, a phosphine oxidecompound, an arylamine compound, a styrylamine compound, or anycombination thereof.

In an embodiment, the emission layer may be a first emission layer thatemits first light, and the organic light-emitting device may furthercomprise between the first electrode and the second electrode i) asecond emission layer that emits second light, or ii) a second emissionlayer that emits second light and a third emission layer that emitsthird light. The first color light and the second color light may beemitted as mixed light, or the first color light, the second colorlight, and the third color light may be emitted as mixed light.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of embodiments ofthe disclosure will be more apparent from the following descriptiontaken in conjunction with the figures.

FIGS. 1 to 4 are each schematic cross-sectional views of organiclight-emitting devices according to embodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings. In this regard, theembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are described below, by referring to the figures, to explainaspects of the invention.

Like reference numerals refer to like elements throughout. In thedrawings, the dimensions of structures are exaggerated for clarity ofillustration. It will be understood that, although the terms first,second, etc. may be used herein to describe various elements, theseelements should not be limited by these terms. These terms are only usedto distinguish one element from another element. Thus, a first elementcould be termed a second element without departing from the teachings ofthe invention. Similarly, a second element could be termed a firstelement. As used herein, the singular forms are intended to include theplural forms as well, unless the context clearly indicates otherwise.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items for the purpose of itsmeaning and interpretation. For example, “A and/or B” may be understoodto mean “A, B, or A and B.” The terms “and” and “or” may be used in theconjunctive or disjunctive sense and may be understood to be equivalentto “and/or”.

The phrase “at least one of” is intended to include the meaning of “atleast one selected from the group of” for the purpose of its meaning andinterpretation. For example, “at least one of A and B” may be understoodto mean “A, B, or A and B.” When preceding a list of elements, the term,“at least one of,” modifies the entire list of elements and does notmodify the individual elements of the list.

It will be further understood that the terms “comprises,” “comprising,”“includes,” and/or “including,” when used in this specification, specifythe presence of stated features, numerals, steps, operations, elements,parts, or the combination thereof, but do not preclude the presence oraddition of one or more other features, numerals, steps, operations,elements, parts, or the combination thereof.

It will also be understood that when a layer, a film, a region, a plate,etc. is referred to as being “on” or “above” another part, it can be“directly on” the other part, or intervening layers may also be present.It will also be understood that when a layer, a film, a region, a plate,etc. is referred to as being “under” or “below” another part, it can be“directly under” the other part, or intervening layers may also bepresent. When an element is referred to as being disposed “on” anotherelement, it can be disposed under the other element.

The spatially relative terms “below”, “beneath”, “lower”, “above”,“upper”, or the like, may be used herein for ease of description todescribe the relations between one element or component and anotherelement or component as illustrated in the drawings. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientation depicted in the drawings. For example, in the case wherea device illustrated in the drawing is turned over, the devicepositioned “below” or “beneath” another device may be placed “above”another device. Accordingly, the illustrative term “below” may includeboth the lower and upper positions. The device may also be oriented inother directions and thus the spatially relative terms may beinterpreted differently depending on the orientations.

Unless otherwise defined, all terms used herein (including technical andscientific terms) have the same meaning as commonly understood by thoseskilled in the art to which this disclosure pertains. It will be furtherunderstood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an ideal or excessively formal sense unlessclearly defined in the specification.

A condensed cyclic compound according to an embodiment is represented byFormula 1:

In Formula 1, B is boron.

In Formula 1, ring A₁ to ring A₅ may each independently be selected froma benzene ring, a naphthalene ring, a pyridine ring, a pyrimidine ring,a pyridazine ring, and a pyrazine ring.

In one embodiment, ring A₁ to ring A₅ may each independently be selectedfrom a benzene ring, a naphthalene ring, and a pyridine ring.

For example, ring A₁ to ring A₅ may each be a benzene ring, butembodiments are not limited thereto.

In Formula 1, Z₁ may be C(R₁) or N, Z₂ may be C(R₂) or N, and Z₃ may beC(R₃) or N. R₁ to R₃ are described below.

In one embodiment, Z₁ may be C(R₁), Z₂ may be C(R₂), and Z₃ may beC(R₃).

X₁ to X₄ in Formula 1 may each independently be selected fromC(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), N(R₁₁), O, and S. R₁₁ and R₁₂ are describedbelow.

In embodiments, in Formula 1,

X₁ to X₄ may each be O or S,

one of X₁ to X₄ may be N(R₁₁), and the others may be O or S,

two of X₁ to X₄ may be N(R₁₁), and the others may be O or S,

three of X₁ to X₄ may be N(R₁₁), and the other may be O or S, or

X₁ to X₄ may each be N(R₁₁).

In embodiments, in Formula 1,

X₁ to X₄ may each be O,

one of X₁ to X₄ may be N(R₁₁), and the others may be O,

two of X₁ to X₄ may be N(R₁₁), and the others may be O,

two of X₁ to X₄ may be N(R₁₁), and one of the others may be O and theother may be S,

three of X₁ to X₄ may be N(R₁₁), and the other may be O,

three of X₁ to X₄ may be N(R₁₁), and the other may be S, or

X₁ to X₄ may each be N(R₁₁).

-(L₂₁L₂₁)_(a21)-(Ar₂₁)_(b21)  Formula 2>

L₂₁ in Formula 2 may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup.

In one embodiment, L₂₁ may be selected from a benzene group, a pentalenegroup, an indene group, a naphthalene group, an azulene group, aheptalene group, an indacene group, an acenaphthene group, a fluorenegroup, a spiro-bifluorene group, a benzofluorene group, a phenalenegroup, a phenanthrene group, an anthracene group, a fluoranthene group,a triphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, pentaphenylene group, ahexacene group, a pyrrole group, an imidazole group, a pyrazole group, apyridine group, a pyrazine group, a pyrimidine group, a pyridazinegroup, an isoindole group, an indole group, an indazole group, a purinegroup, a quinoline group, an isoquinoline group, a benzoquinoline group,a phthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a carbazole group, a dibenzosilolegroup, a phenanthridine group, an acridine group, a phenanthrolinegroup, a phenazine group, a benzoxazole group, a benzimidazole group, afuran group, a benzofuran group, a thiophene group, a benzothiophenegroup, a thiazole group, an isothiazole group, a benzothiazole group, anisooxazole group, an oxazole group, a triazole group, a tetrazole group,an oxadiazole group, a triazine group, a benzoxazole group, adibenzofuran group, a dibenzothiophene group, a benzocarbazole group, adibenzocarbazole group, and a dibenzosilole group; and

a benzene group, a pentalene group, an indene group, a naphthalenegroup, an azulene group, a heptalene group, an indacene group, anacenaphthene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a phenalene group, a phenanthrene group, ananthracene croup, a fluoranthene group, a triphenylene group, a pyrenegroup, a chrysene group, a naphthacene group, a picene group, a perylenegroup, pentaphenylene group, a hexacene group, a pyrrole group, animidazole group, a pyrazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an isoindole group, an indolegroup, an indazole group, a purine group, a quinoline group, anisoquinoline group, a benzoquinoline group, a phthalazine group, anaphthyridine group, a quinoxaline group, a quinazoline group, acinnoline group, a carbazole group, a dibenzosilole group, aphenanthridine group, an acridine group, a phenanthroline group, aphenazine group, a benzoxazole group, a benzimidazole group, a furangroup, a benzofuran group, a thiophene group, a benzothiophene group, athiazole group, an isothiazole group, a benzothiazole group, anisooxazole group, an oxazole group, a triazole group, a tetrazole group,an oxadiazole group, a triazine group, a benzoxazole group, adibenzofuran group, a dibenzothiophene group, a benzocarbazole group, adibenzocarbazole group and a dibenzosilole group, each unsubstituted orsubstituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazine group, a hydrazonegroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenapnthenyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a naphthacenyl group, a picenyl group, a perylenyl group,pentaphenylenyl group, a hexacenyl group, a pyrrolyl group, animidazolyl group, a pyrazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a dibenzosilolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoxazolyl group, a benzimidazolyl group, afuranyl group, a benzofuranyl group, a thiophenyl group, abenzothiophenyl group, a thiazolyl group, an isothiazolyl group, abenzothiazolyl group, an isoxazolyl group, an oxazolyl group, atriazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a benzoxazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and—B(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from hydrogen,deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₆-C₂₀ aryl group, a C₆-C₂₀ aryl group substitutedwith a C₁-C₂₀ alkyl group, a C₆-C₂₀ aryl group substituted with a C₆-C₂₀aryl group, a C₁-C₂₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, and a terphenyl group.

In embodiments, L₂₁ may be a group represented by one of Formulae 3-1 to3-23:

wherein in Formulae 3-1 to 3-23,

Y₁ may be O, S, C(Z₁₃)(Z₁₄), N(Z₁₅), or Si(Z₁₆)(Z₁₇),

Z₁₁ to Z₁₇ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₂₀ alkyl group, a C₂₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, atriazinyl group, a benzimidazolyl group, a phenanthrolinyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

Q₃₁ to Q₃₃ may each independently be selected from hydrogen, deuterium,a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,a C₆-C₂₀ aryl group, a C₆-C₂₀ aryl group substituted with a C₁-C₂₀ alkylgroup, a C₆-C₂₀ aryl group substituted with a C₆-C₂₀ aryl group, aC₁-C₂₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group, and aterphenyl group, and

d3 may be an integer from 0 to 3,

d4 may be an integer from 0 to 4,

d5 may be an integer from 0 to 5,

d6 may be an integer from 0 to 6,

d8 may be an integer from 0 to 8, and

* and *′ each indicate the binding site to a neighboring atom.

a21 in Formula 2 represents the number of repetitions of L₂₁, and a21may be an integer from 0 to 3.

When a21 is 0, -(L₂₁)_(a21)- may be a single bond. When a21 is 2 or 3,two or three L₂₁(s) may be identical to or different from each other.

In one embodiment, a21 in Formula 2 may be 0 or 1. For example, a21 maybe 0, but embodiments are not limited thereto.

Ar₂₁ in Formula 2 may be selected from a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted alkoxy group, asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, and —N(R₁₃)(R₁₄).

In one embodiment, Ar₂₁ may be selected from a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a pentalenyl group, an indenylgroup, a naphthyl group, an azulenyl group, a heptalenyl group, anindacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group,spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, anaphthacenyl group, a picenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pyrrolyl group, an imidazolyl group, apyrazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a purinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoxazolyl group, abenzimidazolyl group, a furanyl group, a benzofuranyl group, athiophenyl group, a benzothiophenyl group, a thiazolyl group, anisothiazolyl group, a benzothiazolyl group, an isoxazolyl group, anoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolylgroup, a triazinyl group, a benzoxazolyl group, a dibenzofuranyl group,a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a dibenzosilolyl group, a phenoxazinyl group, a phenothiazinylgroup, a 9,9-dihydroan acridinyl group, a 1,2,3,4-tetrahydroquinolinylgroup, and a piperidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a pentalenylgroup, an indenyl group, a naphthyl group, an azulenyl group, aheptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenylgroup, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group,spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, anaphthacenyl group, a picenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pyrrolyl group, an imidazolyl group, apyrazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a purinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoxazolyl group, abenzimidazolyl group, a furanyl group, a benzofuranyl group, athiophenyl group, a benzothiophenyl group, a thiazolyl group, anisothiazolyl group, a benzothiazolyl group, an isoxazolyl group, anoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolylgroup, a triazinyl group, a benzoxazolyl group, a dibenzofuranyl group,a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a dibenzosilolyl group, a phenoxazinyl group, a phenothiazinylgroup, a 9,9-dihydroan acridinyl group, a 1,2,3,4-tetrahydroquinolinylgroup, and a piperidinyl group, each unsubstituted or substituted withdeuterium. —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group,an azulenyl group, a heptalenyl group, an indacenyl group, anacenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, aspiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, aspiro-fluorene-benzofluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoxazolyl group, a benzimidazolyl group, afuranyl group, a benzofuranyl group, a thiophenyl group, abenzothiophenyl group, a thiazolyl group, an isothiazolyl group, abenzothiazolyl group, an isoxazolyl group, an oxazolyl group, atriazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a benzoxazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a phenoxazinyl group, a phenothiazinyl group, a9,9-dihydroan acridinyl group, a 1,2,3,4-tetrahydroquinolinyl group, apiperidinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂);and

—N(R₁₃)(R₁₄),

wherein Q₃₁ to Q₃₃ may each independently be selected from hydrogen,deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₆-C₂₀ aryl group, a C₆-C₂₀ aryl group substitutedwith a C₁-C₂₀ alkyl group, a C₆-C₂₀ aryl group substituted with a C₆-C₂₀aryl group, a C₁-C₂₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, and a terphenyl group.

In embodiments, Ar₂₁ may be selected from a group represented by one ofFormulae 5-1 to 5-19 and —N(R₁₃)(R₁₄):

wherein, in Formulae 5-1 to 5-19,

Y₃₁ may be O, S, C(Z₃₃)(Z₃₄), N(Z₃₅), or Si(Z₃₆)(Z₃₇),

W₃₁ may be O, S, or C(Z₃₈)(Z₃₉),

Z₃₁ to Z₃₉ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazine group, a hydrazone group, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenylgroup, a biphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, aphenanthrenyl group, an anthracenyl group, a fluoranthenyl group, atriphenylenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a naphthyridinyl group, a quinoxalinyl group, a quinazolinylgroup, a carbazolyl group, a phenanthridinyl group, an acridinyl group,a phenanthrolinyl group, a phenazinyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂),

e2 may be selected from 1 and 2,

e3 may be an integer from 1 to 3,

e4 may be an integer from 1 to 4,

e6 may be an integer from 1 to 6,

e7 may be an integer from 1 to 5,

e8 may be an integer from 1 to 8,

Q₃₁ to Q₃₃ may each independently be selected from hydrogen, deuterium,a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,a C₆-C₂₀ aryl group, a C₆-C₂₀ aryl group substituted with a C₁-C₂₀ alkylgroup, a C₆-C₂₀ aryl group substituted with a C₆-C₂₀ aryl group, aC₁-C₂₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group, and aterphenyl group, and

* indicates a binding site to a neighboring atom.

In embodiments, Ar₂₁ may be a group represented by one of Formulae 6-1to 6-13:

wherein in Formulae 6-1 to 6-13,

t-Bu may be a tert-butyl group, and Ph indicates may be a phenyl group,and

* indicates a binding site to a neighboring atom.

In Formula 2, b21 represents the number of Ar₂₁ groups substituted inL₂₁, and b21 may be an integer from 1 to 5.

When b21 is 2, 3, 4, or 5, then 2, 3, 4, or 5 Ar₂₁(s) may be identicalto or different from each other.

In one embodiment, b21 may be 1, but embodiments are not limitedthereto.

In one embodiment, a21 in Formula 2 may be 0, Ar₂₁ may be a grouprepresented by one of Formulae 6-1 to 6-13, and b21 may be 1. Forexample, the group represented by Formula 2 may be represented by one ofFormulae 6-1 to 6-13.

R₁ to R₈ in Formula 1 may each independently be selected from a grouprepresented by Formula 2, hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂),—S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), and

R₁₁ to R₁₄ may each independently be selected from a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group.

When at least one of X₁ to X₄ in Formula 1 is selected from C(R₁₁)(R₁₂),Si(R₁₁)(R₁₂), and N(R₁₁), at least one pair of substituents may beoptionally linked via a single bond or a linking group to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, the pair of substituentsselected from the group consisting of R₁₁ and R₁₂, ring A₁ and R₁₁, ringA₄ and R₁₁ ring A₅ and R₁₁ ring A₆ and R₁₁ and ring A₇ and R₁₁.

In one embodiment, when X₁ is selected from C(R₁₁)(R₁₂), Si(R₁₁)(R₁₂),and N(R₁₁), at least one of ring A₁ and R₁₁ and at least one of ring A₆and R₁₁ may optionally be linked via a single bond or a linking group toform a substituted or unsubstituted C₅-C₆₀ carbocyclic group or asubstituted or unsubstituted C₁-C₆₀ heterocyclic group. In embodiments,when X₂ is selected from C(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), and N(R₁₁), at leastone of ring A₆ and R₁₁ and at least one of ring A₇ and R₁₁ mayoptionally be linked via a single bond or a linking group to form aunsubstituted or substituted C₅-C₆₀ carbocyclic group or a unsubstitutedor substituted C₁-C₆₀ heterocyclic group. In embodiments, when X₃ isselected from C(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), and N(R₁₁), at least one ofring A₅ and R₁₁ and at least one of ring A₇ and R₁₁ may optionally belinked via a single bond or a linking group to form a unsubstituted orsubstituted C₅-C₆₀ carbocyclic group or a unsubstituted or substitutedC₁-C₆₀ heterocyclic group. In embodiments, when X₄ is selected fromC(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), and N(R₁₁), at least one of ring A₄ and R₁₁and at least one of ring A₅ and R₁₁ may optionally be linked via asingle bond or a linking group to form a unsubstituted or substitutedC₅-C₆₀ carbocyclic group or a unsubstituted or substituted C₁-C₆₀heterocyclic group.

In Formula 1, c4 to c8 may each independently be an integer from 0 to 6.

In one embodiment, R₁ to R₈ may each independently be selected from agroup represented by Formula 2, hydrogen, deuterium, —F, —Cl, —Br, —I, acyano group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; and

a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group, each substituted withat least one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, aphenyl group, and a biphenyl group.

In one embodiment, R₁ to R₈ may each be hydrogen, or at least one of R₁to R₈ may be a group represented by Formula 2 and the other which is notthe group represented by Formula 2 may be hydrogen.

In one embodiment, R₁₁ to R₁₄ may each independently be selected from:

a C₁-C₂₀ alkyl group;

a C₁-C₂₀ alkyl group, substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a phenylgroup, and a biphenyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a pentalenylgroup, an indenyl group, a naphthyl group, an azulenyl group, aheptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenylgroup, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group,spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, anaphthacenyl group, a picenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pyrrolyl group, an imidazolyl group, apyrazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a purinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoxazolyl group, abenzimidazolyl group, a furanyl group, a benzofuranyl group, athiophenyl group, a benzothiophenyl group, a thiazolyl group, anisothiazolyl group, a benzothiazolyl group, an isoxazolyl group, anoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolylgroup, a triazinyl group, a benzoxazolyl group, a dibenzofuranyl group,a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, and a dibenzosilolyl group; and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a pentalenylgroup, an indenyl group, a naphthyl group, an azulenyl group, aheptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenylgroup, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group,spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, anaphthacenyl group, a picenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pyrrolyl group, an imidazolyl group, apyrazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a purinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoxazolyl group, abenzimidazolyl group, a furanyl group, a benzofuranyl group, athiophenyl group, a benzothiophenyl group, a thiazolyl group, anisothiazolyl group, a benzothiazolyl group, an isoxazolyl group, anoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolylgroup, a triazinyl group, a benzoxazolyl group, a dibenzofuranyl group,a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, and a dibenzosilolyl group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an am idino group, a hydrazine group, a hydrazonegroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group,a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a pentalenyl group, an indenylgroup, a naphthyl group, an azulenyl group, a heptalenyl group, anindacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group,spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, anaphthacenyl group, a picenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pyrrolyl group, an imidazolyl group, apyrazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a purinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoxazolyl group, abenzimidazolyl group, a furanyl group, a benzofuranyl group, athiophenyl group, a benzothiophenyl group, a thiazolyl group, anisothiazolyl group, a benzothiazolyl group, an isoxazolyl group, anoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolylgroup, a triazinyl group, a benzoxazolyl group, a dibenzofuranyl group,a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a dibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and—B(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from hydrogen,deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₆-C₂₀ aryl group, a C₆-C₂₀ aryl group substitutedwith a C₁-C₂₀ alkyl group, a C₆-C₂₀ aryl group substituted with a C₆-C₂₀aryl group, a C₁-C₂₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, and a terphenyl group.

At least one substituent of the substituted C₅-C₆₀ carbocyclic group,the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted alkoxy group, the substituted C₃-C₁₀cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, thesubstituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃),—N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and—P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may eachindependently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, aC₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.

In one embodiment, the condensed cyclic compound may be represented byFormula 1-1:

X₁ to X₄ and R₁ to R₃ in Formula 1-1 are the same as described above inconnection with Formula 1,

R₄₁ to R₄₄ may be understood by referring to the description presentedin connection with R₄ in Formula 1,

R₅₁ to R₅₄ may be understood by referring to the description presentedin connection with R₅ in Formula 1,

R₆₁ to R₆₄ may be understood by referring to the description presentedin connection with R₆ in Formula 1,

R₇₁ to R₇₄ may be understood by referring to the description presentedin connection with R₇ in Formula 1, and

R₈₁ to R₈₃ may be understood by referring to the description presentedin connection with R₈ in Formula 1.

In one embodiment, in Formula 1-1,

R₄₁ to R₄₄, R₅₁ to R₅₄, R₆₁ to R₆₄, R₇₁ to R₇₄, and R₈₁ to R₈₃ may eachbe hydrogen, or

at least one of R₄₁ to R₄₄, R₅₁ to R₅₄, R₆₁ to R₆₄, Rn to R₇₄, and R₈₁to R₈₃ may be a group represented by Formula 2, and the others that arenot the group represented by Formula 2 may be hydrogen.

In embodiments, in Formula 1-1,

R₄₁ to R₄₄, R₅₁ to R₅₄, R₆₁ to R₆₄, R₇₁ to R₇₄, and R₈₁ to R₈₃ may eachbe hydrogen, or

at least one of R₄₂ and R₈₂ may be a group represented by Formula 2, andR₄₁, R₄₃, R₄₄, R₅₁ to R₅₄, R₆₁ to R₆₄, R₇₁ to R₇₄, R₈₁, and R₈₃ may behydrogen.

In embodiments, in Formula 1-1,

R₄₁ to R₄₄, R₅₁ to R₅₄, R₆₁ to R₆₄, R₇₁ to R₇₄, and R₈₁ to R₈₃ may eachbe hydrogen, or

at least one of R₄₂ and R₈₂ may be a group represented by one ofFormulae 6-1 to 6-13, and R₄₁, R₄₃, R₄₄, R₅₁ to R₅₄, R₆₁ to R₆₄, R₇₁ toR₇₄, R₈₁ and R₈₃ may be hydrogen:

In Formulae 6-1 to 6-13, * indicates a binding site to a neighboringatom.

In one embodiment, in Formula 1, X₁ is N(R₁₁) and ring A₁ or ring A₆ islinked to R₁₁ to form a substituted or unsubstituted C₅-C₆₀ carbocyclicgroup or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, X₂ isN(R₁₁) and ring A₆ or ring A₇ is linked to R₁₁ to form a substituted orunsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstitutedC₁-C₆₀ heterocyclic group, X₃ is N(R₁₁) and ring A₅ or ring A₇ is linkedto R₁₁ to form a substituted or unsubstituted C₅-C₆₀ carbocyclic groupor a substituted or unsubstituted C₁-C₆₀ heterocyclic group, or X₄ isN(R₁₁) and ring A₄ or ring A₅ is linked to R₁₁ to form a substituted orunsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstitutedC₁-C₆₀ heterocyclic group.

For example, the condensed cyclic compound may be represented by one ofFormulae 1-1A to 1-1F:

wherein in Formulae 1-1A to 1-1F,

X₁ to X₄ and R₁ to R₃ are the same as described above presented inconnection with Formula 1,

R₄₁ to R₄₄ may be understood by referring to the description presentedin connection with R₄ in Formula 1,

R₅₁ to R₅₄ may be understood by referring to the description presentedin connection with R₅ in Formula 1,

R₆₁ to R₆₄ may be understood by referring to the description presentedin connection with R₆ in Formula 1,

R₇₁ to R₇₄ may be understood by referring to the description presentedin connection with R₇ in Formula 1,

R₈₁ to R₈₃ may be understood by referring to the description presentedin connection with R₈ in Formula 1, and

R₁₁₁ to R₁₁₄ may be understood by referring to the description presentedin connection with R₁ in Formula 1.

For example, R₁₁₁ to R₁₁₄ in Formulae 1-1A to 1-1F may each be hydrogen.

In one embodiment, the condensed cyclic compound may be selected fromCompounds 1 to 37, but embodiments are not limited thereto:

The condensed cyclic compound represented by Formula 1 is capable ofreverse intersystem crossing from a triplet excited state to a singletexcited state through thermal activity even at room temperature,resulting in delayed fluorescence. Since excitons in the triplet stateare used for emission, emission efficiency may be improved.

In one embodiment, the condensed cyclic compound represented by Formula1 may satisfy the following Equation 1.

ΔE _(ST) =S1−T1≤0.3 eV  <Equation 1>

S1 is the singlet energy level of the condensed cyclic compound, and

T1 is the triplet energy level of the condensed cyclic compound.

Since the condensed cyclic compound according to the embodiment includesthe condensed cyclic structure represented by Formula 1, the highestoccupied molecular orbital (HOMO) and the lowest unoccupied molecularorbital (LUMO) are separated by multiple resonance between an N atom anda B atom to obtain thermally active delayed fluorescent (TADF)characteristic. Since the condensed cyclic compound contains three boronatoms and has a wide plate-like skeleton, the condensed cyclic compoundhas a structure favorable to multiple resonances, and thus may have highoscillator strength (f) and low ΔE_(ST). Thus, the condensed cycliccompound may exhibit improved TADF properties.

Since the condensed cyclic compound has a rigid skeleton in whichcondensed cyclic group moieties, including boron atoms, share a benzenering and are condensed, the structural change before and after thetransition is small, thereby improving stability.

The reduction in structural relaxation during the electron transferprocess can also be seen as a decrease in the Stokes shift. In thecondensed cyclic compound, the absorption band shifts to a longerwavelength due to the increase in the conjugate system. However, sincethe Stokes shift is reduced, the increase in the emission wavelength canbe suppressed as much as possible. When the condensed cyclic compound isincluded as a dopant of an emission layer, a host may be selected from agroup of host materials emitting long wavelengths of light havingrelatively low S1 energy, thereby helping device stability.

The condensed cyclic compound is condensed with seven ring structures,and has a long molecular length and a wide plate-like skeleton, so thatthe non-localized region of the electron is enlarged and polarizationeasily occurs and thus the f value may be further increased.

In the condensed cyclic compound, nitrogen (N) has energy correspondingto HOMO, boron (B) has energy corresponding to LUMO, and respectivecarbon (C) adjacent to N and B may alternately have energy correspondingto HOMO/LUMO due to the resonance effect. As such, since, in the case ofthe condensed cyclic compound, HOMO and LUMO are separated at the atomiclevel, TADF properties can be expressed. Since the structures accordingto the disclosure contain nitrogen atoms, oxygen atoms, sulfur atoms,and three boron atoms, and thus there are many donors and manyacceptors, the resonance is amplified and the HOMO/LUMO separationeffect may be increased. Due to the inclusion of boron atoms, the “shortrange CT” phenomenon, in which the separation of HOMO and LUMO ofcrossing atoms is more enhanced than DABNA−1 that includes one boronatom, can be obtained, and by widening the molecular plane, electrondelocalization can be expanded, polarizability can be increased, andthus, the f value may be further increased. Therefore, the organiclight-emitting device including the condensed cyclic compound may havehigh efficiency.

When a substituent having an electron donating characteristic isincluded in the para position of the boron atom of the condensed cycliccompound (for example, R₄₂ and/or R₈₂ in Formula 1-1), the oscillatorstrength of the compound represented by Formula 1 may be furtherincreased. Accordingly, since the probability of transition to a higherorder triplet of T1 or more can be increased when the molecule istransferred, E_(st) values may be decreased and the condensed cycliccompound may have improved TADF properties. Since the substituent havingthe electron donor property increases the electron density of the boronatom, the behaviors in which the electron donor nucleophile approachesfrom outside the molecule and form a bond, or a compound decomposes maybe prevented. As a result, the stability of the condensed cycliccompound may be increased.

Furthermore, since the condensed cyclic compound represented by Formula1 has relatively high charge (hole or electron) transport ability, anexciton formation ratio in an emission layer of an organiclight-emitting device using the condensed cyclic compound represented byFormula 1 may be improved. Accordingly, the organic light-emittingdevice may have low driving voltage, high efficiency, long lifespan, andhigh maximum quantum efficiency.

Synthesis methods of the condensed cyclic compound represented byFormula 1 may be recognizable by one of ordinary skill in the art byreferring to Examples provided below.

At least one of such condensed cyclic compounds represented by Formula 1may be used between a pair of electrodes of an organic light-emittingdevice. For example, the condensed cyclic compounds may be included inat least one selected from a hole transport region, an electrontransport region, and an emission layer. In embodiments, the condensedcyclic compound represented by Formula 1 may be used as a material for acapping layer located outside the pair of electrodes of an organiclight-emitting device.

Accordingly, an organic light-emitting device may include a firstelectrode; a second electrode facing the first electrode; an organiclayer disposed between the first electrode and the second electrode andincluding an emission layer; and a condensed cyclic compound representedby Formula 1.

In embodiments, the organic light-emitting device may include at leastone condensed cyclic compound represented by Formula 1.

In one embodiment, the organic layer of the organic light-emittingdevice may include the condensed cyclic compound represented by Formula1.

In one embodiment, the first electrode may be an anode,

the second electrode may be a cathode,

the organic layer may include the condensed cyclic compound representedby Formula 1,

a hole transport region disposed between the first electrode and theemission layer, and an electron transport region disposed between theemission layer and the second electrode.

The hole transport region may include a hole injection layer, a holetransport layer, an emission auxiliary layer, an electron blockinglayer, or any combination thereof.

The electron transport region may include a buffer layer, a holeblocking layer, an electron transport layer, an electron injectionlayer, or any combination thereof.

In one embodiment, the emission layer of the organic light-emittingdevice may include the condensed cyclic compound.

For example, the condensed cyclic compound included in the emissionlayer may be a thermally activated delayed fluorescence emitter (TADFemitter), and the emission layer may emit delayed fluorescence.

In one embodiment, the emission layer may further include a host, thecondensed cyclic compound included in the emission layer is a dopant,and an amount of the host included in the emission layer may be greaterthan an amount of the condensed cyclic compound included in the emissionlayer. For example, the amount of the condensed cyclic compound may befrom about 0.01 parts by weight to about 49.99 parts by weight based on100 parts by weight of the emission layer.

For example, the host included in the emission layer may include ananthracene compound, a carbazole compound, a benzimidazole compound, aphosphine oxide compound, an arylamine compound, a styrylamine compound,or any combination thereof.

In one embodiment, the emission layer of the organic light-emittingdevice may include the condensed cyclic compound, and the emission layermay emit light having a wavelength of maximum emission of about 420 nmto about 480 nm.

In one embodiment, in the organic light-emitting device, the emissionlayer may be a first emission layer that emits first light. The organiclight-emitting device may further include, between the first electrodeand the second electrode, i) at least one second emission layer thatemits second light, or ii) at least one second emission layer that emitssecond light and at least one third emission layer that emits thirdlight.

The first light and the second light may be emitted as mixed light, orthe first light, the second light, and the third light may be emitted asmixed light.

In one embodiment, the first light, the second light, and the thirdlight may have colors different from each other.

In embodiments, a wavelength of maximum emission of the first light, awavelength of maximum emission of the second light, and a wavelength ofmaximum emission of the third light may be identical to or differentfrom each other.

In one embodiment, provided is an electronic apparatus which may includethe organic light-emitting device and a thin-film transistor, whereinthe first electrode of the organic light-emitting device mayelectrically contact one of the source electrode and drain electrode ofthe thin-film transistor.

The term “an organic layer” as used herein refers to a single layer ormultiple layers located between the first electrode and the secondelectrode of an organic light-emitting device. A material included inthe “organic layer” is not limited to an organic material.

[Description of FIG. 1]

FIG. 1 is a schematic cross-sectional view of an organic light-emittingdevice 10 according to an embodiment. The organic light-emitting device10 includes a first electrode 110, an organic layer 150, and a secondelectrode 190.

Hereinafter, the structure of the organic light-emitting device 10according to an embodiment and a method of manufacturing the organiclight-emitting device 10 will be described in connection with FIG. 1.

[First Electrode 110]

In FIG. 1, a substrate may be disposed under the first electrode 110 orabove the second electrode 190. The substrate may be a glass substrateor a plastic substrate, each having excellent mechanical strength,thermal stability, transparency, surface smoothness, ease of handling,and water resistance.

The first electrode 110 may be formed by depositing or sputtering amaterial for forming the first electrode 110 on the substrate. When thefirst electrode 110 is an anode, the material for forming the firstelectrode 110 may be selected from materials with a high work functionto facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-reflectiveelectrode, or a transmissive electrode. When the first electrode 110 isa transmissive electrode, a material for forming a first electrode maybe selected from indium tin oxide (ITO), indium zinc oxide (IZO), tinoxide (SnO₂), zinc oxide (ZnO), and any combinations thereof, butembodiments are not limited thereto. In embodiments, when the firstelectrode 110 is a semi-transmissive electrode or a reflectiveelectrode, a material for forming the first electrode 110 may beselected from magnesium (Mg), silver (Ag), aluminum (Al),aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In),magnesium-silver (Mg—Ag), and any combinations thereof, but embodimentsare not limited thereto.

The first electrode 110 may have a single-layered structure, or amulti-layered structure including two or more layers. For example, thefirst electrode 110 may have a three-layered structure of ITO/Ag/ITO,but the structure of the first electrode 110 is not limited thereto.

[Organic Layer 150]

The organic layer 150 is disposed on the first electrode 110. Theorganic layer 150 may include an emission layer.

The organic layer 150 may further include a hole transport regiondisposed between the first electrode 110 and the emission layer and anelectron transport region disposed between the emission layer and thesecond electrode 190.

[Hole Transport Region in Organic Layer 150]

The hole transport region may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including differentmaterials, or iii) a multi-layered structure having multiple layersincluding different materials.

The hole transport region may include a hole injection layer, a holetransport layer, an emission auxiliary layer, an electron blockinglayer, or any combination thereof.

For example, the hole transport region may have a single-layeredstructure including a single layer including different materials, or amulti-layered structure having a hole injection layer/hole transportlayer structure, a hole injection layer/hole transport layer/emissionauxiliary layer structure, a hole injection layer/emission auxiliarylayer structure, a hole transport layer/emission auxiliary layerstructure, or a hole injection layer/hole transport layer/electronblocking layer structure, wherein for each structure, constitutinglayers may be sequentially stacked (or disposed) from the firstelectrode 110 in this stated order, but the structure of the holetransport region is not limited thereto.

The hole transport region may include at least one selected fromm-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, spiro-TPD, spiro-NPB,methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine(TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound representedby Formula 201 below, and a compound represented by Formula 202 below:

In Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted orunsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstitutedC₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer from 0 to 3,

xa5 may be an integer from 1 to 10, and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In one embodiment, in Formula 202, R₂₀₁ and R₂₀₂ may optionally belinked to each other via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group, and R₂₀₃ and R₂₀₄ may optionally be linked toeach other via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group.

In embodiments, in Formulae 201 and 202,

L₂₀₁ to L₂₀₅ may each independently be selected from:

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anindacenylene group, an acenaphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenalenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, anaphthacenylene group, a picenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, arubicenylene group, a coronenylene group, an ovalenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group; and

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anindacenylene group, an acenaphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenalenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, anaphthacenylene group, a picenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, arubicenylene group, a coronenylene group, an ovalenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an am idino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In embodiments, xa1 to xa4 may each independently be 0, 1, or 2.

In embodiments, xa5 may be 1, 2, 3, or 4.

In embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selectedfrom:

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group,an indenyl group, a naphthyl group, an azulenyl group, a heptalenylgroup, an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group,an indenyl group, a naphthyl group, an azulenyl group, a heptalenylgroup, an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an am idino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

Q₃₁ to Q₃₃ are the same as described above.

In embodiments, at least one selected from R₂₀₁ to R₂₀₃ in Formula 201may each independently be selected from:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkylgroup, a phenyl group substituted with —F, a naphthyl group, a fluorenylgroup, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranylgroup, and a dibenzothiophenyl group,

but embodiments are not limited thereto.

In embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may be linked to eachother via a single bond, and/or ii) R₂₀₃ and R₂₀₄ may be linked to eachother via a single bond.

In embodiments, at least one selected from R₂₀₁ to R₂₀₄ in Formula 202may be selected from:

a carbazolyl group; and

a carbazolyl group substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, acarbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but embodiments are not limited thereto.

The compound represented by Formula 201 may be represented by Formula201-1 below:

In one embodiment, the compound represented by Formula 201 may berepresented by Formula 201-2 below, but embodiments are not limitedthereto:

In embodiments, the compound represented by Formula 201 may berepresented by Formula 201-2(1) below, but embodiments are not limitedthereto:

The compound represented by Formula 201 may be represented by Formula201A below:

In one embodiment, the compound represented by Formula 201 may berepresented by Formula 201A(1) below, but embodiments are not limitedthereto:

In embodiments, the compound represented by Formula 201 may berepresented by Formula 201A-1 below, but embodiments are not limitedthereto:

In one embodiment, the compound represented by Formula 202 may berepresented by Formula 202-1 below:

In embodiments, the compound represented by Formula 202 may berepresented by Formula 202-1(1) below:

In one embodiment, the compound represented by Formula 202 may berepresented by Formula 202A below:

In embodiments, the compound represented by Formula 202 may berepresented by Formula 202A-1 below:

In Formulae 201-1, 201-2, 201-2(1), 201A, 201A(1), 201A-1, 202-1,202-1(1), 202A, and 202A-1,

L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ may each be understoodby referring to the corresponding descriptions thereof presented herein,

L₂₀₅ may be selected from a phenylene group and a fluorenylene group,

X₂₁₁ may be selected from O, S, and N(R₂₁₁),

X₂₁₂ may be selected from O, S, and N(R₂₁₂),

R₂₁₁ and R₂₁₂ may each be understood by referring to the descriptionsprovided in connection with R₂₀₃, and

R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an am idino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group.

The hole transport region may include at least one compound selectedfrom Compounds HT1 to HT48 below, but embodiments are not limitedthereto:

A thickness of the hole transport region may be from about 100 Å toabout 10,000 Å. In an embodiment, the thickness of the hole transportregion may be from about 100 Å to about 1,000 Å. When the hole transportregion includes at least one selected from a hole injection layer and ahole transport layer, a thickness of the hole injection layer may be ina range of about 100 Å to about 9,000 Å, and a thickness of the holetransport layer may be in a range of about 50 Å to about 2,000 Å. In anembodiment, the thickness of the hole injection layer may be in a rangeof 100 Å to about 1,000 Å. In an embodiment, the thickness of the holetransport layer may be in a range of about 100 Å to about 1,500 Å. Whenthe thicknesses of the hole transport region, the hole injection layer,and the hole transport layer are within these ranges, satisfactory holetransporting characteristics may be obtained without a substantialincrease in driving voltage.

The emission auxiliary layer may increase light-emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by an emission layer, and the electronblocking layer may block the flow of electrons from an electrontransport region. The emission auxiliary layer and the electron blockinglayer may include the materials as described above.

[p-Dopant]

The hole transport region may further include a charge-generationmaterial for the improvement of conductive properties. Thecharge-generation material may be homogeneously or non-homogeneouslydispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant.

In one embodiment, the p-dopant may have a LUMO energy level of −3.5 eVor less.

The p-dopant may include at least one selected from a quinonederivative, a metal oxide, and a cyano group-containing compound, butembodiments are not limited thereto.

In one embodiment, the p-dopant may include at least one selected from:

a quinone derivative, such as tetracyanoquinodimethane (TCNQ) or2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);

a metal oxide, such as tungsten oxide or molybdenum oxide;

1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and

a compound represented by Formula 221 below:

but embodiments are not limited thereto:

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, wherein at least oneselected from R₂₂₁ to R₂₂₃ may have at least one substituent selectedfrom a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substitutedwith —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl groupsubstituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

[Emission Layer in Organic Layer 150]

When the organic light-emitting device 10 is a full-color organiclight-emitting device, the emission layer may be patterned into a redemission layer, a green emission layer, or a blue emission layer,according to a sub-pixel. In embodiments, the emission layer may have astacked structure of two or more layers selected from a red emissionlayer, a green emission layer, and a blue emission layer, in which thetwo or more layers contact each other or are separated from each other.In embodiments, the emission layer may include two or more materialsselected from a red light-emitting material, a green light-emittingmaterial, and a blue light-emitting material, in which the two or morematerials are mixed with each other in a single layer to emit whitelight.

The emission layer may include a host and a dopant. The dopant mayinclude at least one selected from a phosphorescent dopant and afluorescent dopant.

In the emission layer, an amount of the dopant may be in a range ofabout 0.01 parts by weight to about 15 parts by weight based on 100parts by weight of the host, but embodiments are not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å. In an embodiment, the thickness of the emission layer maybe in a range of about 200 Å to about 600 Å. When the thickness of theemission layer is within this range, excellent light-emissioncharacteristics may be obtained without a substantial increase indriving voltage.

[Host in Emission Layer]

In embodiments, the host may include a compound represented by Formula301 below:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  <Formula 301>

In Formula 301,

Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an am idino group, a hydrazino group, ahydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂),

xb21 may be an integer from 1 to 5, and

Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀ alkylgroup, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but embodiments are not limitedthereto.

In one embodiment, Ar₃₀₁ in Formula 301 may be selected from:

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup; and

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but embodiments are not limitedthereto.

When xb11 in Formula 301 is 2 or more, two or more Ar₃₀₁(s) may belinked to each other via a single bond.

In embodiments, the compound represented by Formula 301 may berepresented by Formula 301-1 or 301-2 below:

In Formulae 301-1 and 301-2,

A₃₀₁ to A₃₀₄ may each independently be selected from a benzene, anaphthalene, a phenanthrene, a fluoranthene, a triphenylene, a pyrene, achrysene, a pyridine, a pyrimidine, an indene, a fluorene, aspiro-bifluorene, a benzofluorene, a dibenzofluorene, an indole, acarbazole, benzocarbazole, dibenzocarbazole, a furan, a benzofuran, adibenzofuran, a naphthofuran, a benzonaphthofuran, dinaphthofuran, athiophene, a benzothiophene, a dibenzothiophene, a naphthothiophene, abenzonaphthothiophene, and a dinaphthothiophene,

X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄],

R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ may each be understood by referring tothe corresponding descriptions presented herein,

L₃₀₂ to L₃₀₄ may each be understood by referring to the descriptionpresented in connection with L₃₀₁,

xb2 to xb4 may each be understood by referring to the descriptionpresented in connection with xb1₇ and

R₃₀₂ to R₃₀₄ may each be understood by referring to the descriptionpresented in connection with R₃₀₁.

For example, L₃₀₁ to L₃₀₄ in Formulae 301, 301-1, and 301-2 may eachindependently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an am idino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ are the same as described above.

In one embodiment, R₃₀₁ to R₃₀₄ in Formulae 301, 301-1, and 301-2 mayeach independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an am idino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ are the same as described above.

In embodiments, the host may include an alkaline earth metal complex.For example, the host may be selected from a Be complex (for example,Compound H55), a Mg complex, and a Zn complex.

The host may include at least one selected from9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene(mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H55below, but embodiments are not limited thereto:

[Phosphorescent Dopant Included in Emission Layer in Organic Layer 150]

The phosphorescent dopant may include an organometallic complexrepresented by Formula 401 below:

M(L₄₀₁)_(xc1)(L₄₀₂)_(xc2)  <Formula 401>

In Formulae 401 and 402,

M may be selected from iridium (Ir), platinum (Pt), palladium (Pd),osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu),terbium (Tb), rhodium (Rh), and thulium (Tm),

L₄₀₁ may be selected from ligands represented by Formula 402, and xc1may be 1, 2, or 3, wherein, when xc1 is 2 or more, two or more L₄₀₁(s)may be identical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be an integer from 0 to 4,wherein, when xc2 is 2 or more, two or more L₄₀₂(s) may be identical toor different from each other,

X₄₀₁ to X₄₀₄ may each independently be nitrogen or carbon,

X₄₀₁ and X₄₀₃ may be linked to each other via a single bond or a doublebond, and X₄₀₂ and X₄₀₄ may be linked to each other via a single bond ora double bond,

A₄₀₁ and A₄₀₂ may each independently be selected from a C₅-C₆₀carbocyclic group or a C₁-C₆₀ heterocyclic group,

X₄₀₅ may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)-*′,*—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)═C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C(Q₄₁₁)=*′,wherein Q₄₁₁ and Q₄₁₂ may be hydrogen, deuterium, a C₁-C₂₀ alkyl group,a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, or a naphthyl group,

X₄₀₆ may be a single bond, O, or S,

R₄₀₁ and R₄₀₂ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, asubstituted or unsubstituted C₁-C₂₀ alkyl group, a substituted orunsubstituted C₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃),—N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and—P(═O)(Q₄₀₁)(Q₄₀₂), and Q₄₀₁ to Q₄₀₃ may each independently be selectedfrom a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₂₀ aryl group,and a C₁-C₂₀ heteroaryl group,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *′ in Formula 402 each indicate a binding site to M in Formula401.

In one embodiment, A₄₀₁ and A₄₀₂ in Formula 402 may each independentlybe selected from a benzene group, a naphthalene group, a fluorene group,a spiro-bifluorene group, an indene group, a pyrrole group, a thiophenegroup, a furan group, an imidazole group, a pyrazole group, a thiazolegroup, an isothiazole group, an oxazole group, an isoxazole group, apyridine group, a pyrazine group, a pyrimidine group, a pyridazinegroup, a quinoline group, an isoquinoline group, a benzoquinoline group,a quinoxaline group, a quinazoline group, a carbazole group, abenzimidazole group, a benzofuran group, a benzothiophene group, anisobenzothiophene group, a benzoxazole group, an isobenzoxazole group, atriazole group, a tetrazole group, an oxadiazole group, a triazinegroup, a dibenzofuran group, and a dibenzothiophene group.

In embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, and X₄₀₂ may becarbon, or ii) X₄₀₁ and X₄₀₂ may each be nitrogen.

In embodiments, R₄₀₁ and R₄₀₂ in Formula 501 may each independently beselected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group,a cyclohexyl group, an adamantanyl group, a norbornanyl group, and anorbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group a phenyl group, a biphenyl group,a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group; and

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁),—S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂),

wherein Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group,and a naphthyl group, but embodiments are not limited thereto.

In embodiments, when xc1 in Formula 401 is 2 or more, two A₄₀₁(s) in twoor more L₄₀₁(s) may optionally be linked to each other via X₄₀₇, whichis a linking group, or two A₄₀₂(s) in two or more L₄₀₁(s) may optionallybe linked to each other via X₄₀₈, which is a linking group (seeCompounds PD1 to PD4 and PD7). X₄₀₇ and X₄₀₈ may each independently be asingle bond, *—O—*′, *—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or*—C(Q₄₁₃)═C(Q₄₁₄)*′ (wherein Q₄₁₃ and Q₄₁₄ may each independently behydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, or a naphthyl group),but are not limited thereto.

L₄₀₂ in Formula 401 may be a monovalent, divalent, or trivalent organicligand. For example, L₄₀₂ may be selected from halogen, diketone (forexample, acetylacetonate), carboxylic acid (for example, picolinate),—C(═O), isonitrile, —CN, and phosphorus (for example, phosphine orphosphite), but embodiments are not limited thereto.

In embodiments, the phosphorescent dopant may be selected from, forexample, Compounds PD1 to PD25 below, but embodiments are not limitedthereto:

[Fluorescent Dopant in Emission Layer]

The fluorescent dopant may include the condensed-cyclic compoundrepresented by Formula 1. The condensed cyclic compound represented byFormula 1 may be a thermally active delayed fluorescence emitter.

The fluorescent dopant may further include an arylamine compound or astyrylamine compound.

The fluorescent dopant may include a compound represented by Formula 501below:

In Formula 501,

Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be an integer from 0 to 3,

R₅₀₁ and R₅₀₂ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and

xd4 may be an integer from 1 to 6.

In one embodiment, Ar₅₀₁ in Formula 501 may be selected from:

a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup; and

a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group,a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In embodiments, L₅₀₁ to L₅₀₃ in Formula 501 may each independently beselected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an am idino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group.

In embodiments, R₅₀₁ and R₅₀₂ in Formula 501 may each independently beselected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an am idino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In embodiments, xd4 in Formula 501 may be 2, but embodiments are notlimited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1to FD22 below:

In embodiments, the fluorescent dopant may be selected from thefollowing compounds, but embodiments are not limited thereto.

[Electron Transport Region in Organic Layer 150]

The electron transport region may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including differentmaterials, or iii) a multi-layered structure having multiple layersincluding different materials.

The electron transport region may include a buffer layer, a holeblocking layer, an electron control layer, an electron transport layer,an electron injection layer, or any combination thereof, but embodimentsare not limited thereto.

For example, the electron transport region may have an electrontransport layer/electron injection layer structure, a hole blockinglayer/electron transport layer/electron injection layer structure, anelectron control layer/electron transport layer/electron injection layerstructure, or a buffer layer/electron transport layer/electron injectionlayer structure, wherein for each structure, constituting layers may besequentially stacked (or disposed) from an emission layer. However,embodiments of the structure of the electron transport region are notlimited thereto.

The electron transport region (for example, a buffer layer, a holeblocking layer, an electron control layer, or an electron transportlayer in the electron transport region) may include a metal-freecompound containing at least one 7 electron-depleted nitrogen-containingring.

The “π electron-depleted nitrogen-containing ring” indicates a C₁-C₆₀heterocyclic group having at least one *—N═*′ moiety as a ring-formingmoiety.

For example, the “π electron-depleted nitrogen-containing ring” may bei) a 5-membered to 7-membered heteromonocyclic group having at least one*—N═*′ moiety, ii) a heteropolycyclic group in which two or more5-membered to 7-membered heteromonocyclic groups each having at leastone *—N═*′ moiety are condensed with each other, or iii) aheteropolycyclic group in which at least one of 5-membered to 7-memberedheteromonocyclic groups, each having at least one *—N═*′ moiety, iscondensed with at least one C₅-C₆₀ carbocyclic group.

Examples of the π electron-depleted nitrogen-containing ring include animidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, anisoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, anindazole, a purine, a quinoline, an isoquinoline, a benzoquinoline, aphthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline,a phenanthridine, an acridine, a phenanthroline, a phenazine, abenzimidazole, an isobenzothiazole, a benzoxazole, an isobenzoxazole, atriazole, a tetrazole, an oxadiazole, a triazine, a thiadiazole, animidazopyridine, an imidazopyrimidine, and an azacarbazole, but are notlimited thereto.

For example, the electron transport region may include a compoundrepresented by Formula 601 below:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  <Formula 601>

In Formula 601,

Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xe11 may be 1, 2, or 3,

L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xe1 may be an integer from 0 to 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁),—S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or anaphthyl group, and

xe21 may be an integer from 1 to 5.

In one embodiment, at least one of Ar₆₀₁(s) in the number of xe11 andR₆₀₁(s) in the number of xe21 may include the π electron-depletednitrogen-containing ring.

In one embodiment, Ar₆₀₁ in Formula 601 may be selected from:

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group; and

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an am idino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

When xe11 in Formula 601 is 2 or more, two or more Ar₆₀₁(s) may belinked to each other via a single bond.

In embodiments, Ar₆₀₁ in Formula 601 may be an anthracene group.

In embodiments, a compound represented by Formula 601 may be representedby Formula 601-1 below:

In Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), and at least one selected from X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each be understood by referring to the descriptionsprovided in connection with L₆₀₁,

xe611 to xe613 may each be understood by referring to the descriptionpresented in connection with xe1,

R₆₁₁ to R₆₁₃ may each be understood by referring to the descriptionsprovided in connection with R₆₀₁, and

R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In one embodiment, L₆₀₁ and L₆₁₁ to L₆₁₃ in Formulae 601 and 601-1 mayeach independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an am idino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, and an azacarbazolyl group,

but embodiments are not limited thereto.

In embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 mayeach independently be 0, 1, or 2.

In embodiments, R₆₀₁ and R₆₁₁ to R₆₁₃ in Formulae 601 and 601-1 may eachindependently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an am idino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂), and

Q₆₀₁ and Q₆₀₂ are the same as described above.

The electron transport region may include at least one compound selectedfrom Compounds ET1 to ET36 below, but embodiments are not limitedthereto:

In embodiments, the electron transport region may include at least onecompound selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq,3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ), and NTAZ below:

A thickness of the buffer layer, the hole blocking layer, or theelectron control layer may be in a range of about 20 Å to about 1,000 Å.In an embodiment, the thickness of the buffer layer may be in a range ofabout 30 Å to about 300 Å. In an embodiment, the thickness of the holeblocking layer may be in a range of about 30 Å to about 300 Å. In anembodiment, the thickness of the electron control layer may be in arange of about 30 Å to about 300 Å. When the thicknesses of the bufferlayer, the hole blocking layer, and the electron control layer arewithin these ranges, the electron blocking layer may have excellentelectron blocking characteristics or electron control characteristicswithout a substantial increase in driving voltage.

A thickness of the electron transport layer may be from about 100 Å toabout 1,000 Å. In an embodiment, the thickness of the electron transportlayer may be from about 150 Å to about 500 Å. When the thickness of theelectron transport layer is within the ranges described above, theelectron transport layer may have satisfactory electron transportcharacteristics without a substantial increase in driving voltage.

The electron transport region (for example, the electron transport layerin the electron transport region) may further include a metal-containingmaterial.

The metal-containing material may include at least one selected fromalkali metal complex and alkaline earth-metal complex. The alkali metalcomplex may include a metal ion selected from a Li ion, a Na ion, a Kion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex mayinclude a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Srion, and a Ba ion. A ligand coordinated with the metal ion of the alkalimetal complex or the alkaline earth-metal complex may be selected from ahydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, ahydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, ahydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxydiphenylthiadiazole, a hydroxy phenylpyridine, a hydroxyphenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, aphenanthroline, and a cyclopentadiene, but embodiments are not limitedthereto.

For example, the metal-containing material may include a Li complex. TheLi complex may include, for example, Compound ET-D1 (lithium quinolate,LiQ) or ET-D2 below:

The electron transport region may include an electron injection layerthat facilitates electron injection from the second electrode 190. Theelectron injection layer may be in direct contact with the secondelectrode 190.

The electron injection layer may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including differentmaterials, or iii) a multi-layered structure having multiple layersincluding different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combination thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In oneembodiment, the alkali metal may be Li, Na, or Cs. In embodiments, thealkali metal may be Li or Cs, but embodiments are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth-metal compound, and therare earth metal compound may be selected from oxides and halides (forexample, fluorides, chlorides, bromides, or iodides) of the alkalimetal, the alkaline earth-metal, and the rare earth metal.

The alkali metal compound may be selected from alkali metal oxides, suchas Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF,KF, LiI, NaI, CsI, or KI. In one embodiment, the alkali metal compoundmay be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, butembodiments are not limited thereto.

The alkaline earth-metal compound may be selected from alkalineearth-metal oxides, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (0<x<1), orBa_(x)Ca_(1-x)O (0<x<1). In one embodiment, the alkaline earth-metalcompound may be selected from BaO, SrO, and CaO, but embodiments are notlimited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, Sc₂O₃,Y₂O₃, Ce₂O₃, GdF₃ and TbF₃. In one embodiment, the rare earth metalcompound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃,but embodiments are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rareearth metal complex may include an ion of alkali metal, alkalineearth-metal, and rare earth metal as described above, and a ligandcoordinated with a metal ion of the alkali metal complex, the alkalineearth-metal complex, or the rare earth metal complex may be selectedfrom hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline,hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxyphenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazole,hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene,but embodiments are not limited thereto.

The electron injection layer may consist of an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combination thereof, as described above. In embodiments, theelectron injection layer may further include an organic material. Whenthe electron injection layer further includes an organic material, thenan alkali metal, an alkaline earth metal, a rare earth metal, an alkalimetal compound, an alkaline earth-metal compound, a rare earth metalcompound, an alkali metal complex, an alkaline earth-metal complex, arare earth metal complex, or any combinations thereof may behomogeneously or non-homogeneously dispersed in a matrix including theorganic material.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å. In an embodiment, the thickness of the electroninjection layer may be in a range of about 3 Å to about 90 Å. When athickness of the electron injection layer is within these ranges,satisfactory electron injection characteristics may be obtained withoutsubstantial increase in driving voltage.

[Second Electrode 190]

The second electrode 190 is located on the organic layer 150 having sucha structure. The second electrode 190 may be a cathode which is anelectron injection electrode, and in this regard, a material for formingthe second electrode 190 may be selected from metal, an alloy, anelectrically conductive compound, and a combination thereof, which havea relatively low work function.

The second electrode 190 may include at least one selected from lithium(Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium(Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver(Mg—Ag), ITO, and IZO, but embodiments are not limited thereto. Thesecond electrode 190 may be a transmissive electrode, asemi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or amulti-layered structure including two or more layers.

[Description of FIGS. 2 to 4]

An organic light-emitting device 20 of FIG. 2 has a structure in which afirst capping layer 210, the first electrode 110, the organic layer 150,and the second electrode 190 are sequentially stacked (or disposed) inthis stated order. An organic light-emitting device 30 of FIG. 3 has astructure in which the first electrode 110, the organic layer 150, thesecond electrode 190, and a second capping layer 220 are sequentiallystacked (or disposed) in this stated order. An organic light-emittingdevice 40 of FIG. 4 has a structure in which the first capping layer210, the first electrode 110, the organic layer 150, the secondelectrode 190, and the second capping layer 220 are sequentially stacked(or disposed) in this stated order.

Regarding FIGS. 2 to 4, the first electrode 110, the organic layer 150,and the second electrode 190 may be understood by referring to thecorresponding descriptions provided in connection with FIG. 1.

In the organic layer 150 of each of the organic light-emitting devices20 and 40, light generated in an emission layer may pass through thefirst electrode 110 and the first capping layer 210 toward the outside,wherein the first electrode 110 may be a semi-transmissive electrode ora transmissive electrode. In the organic layer 150 of each of theorganic light-emitting devices 30 and 40, light generated in an emissionlayer may pass through the second electrode 190 and the second cappinglayer 220 toward the outside, wherein the second electrode 190 may be asemi-transmissive electrode or a transmissive electrode.

The first capping layer 210 and the second capping layer 220 mayincrease external luminescence efficiency according to the principle ofconstructive interference.

The first capping layer 210 and the second capping layer 220 may eachindependently be an organic capping layer including an organic material,an inorganic capping layer including an inorganic material, or acomposite capping layer including an organic material and an inorganicmaterial.

At least one selected from the first capping layer 210 and the secondcapping layer 220 may each independently include at least one materialselected from carbocyclic compounds, heterocyclic compounds, amine-basedcompounds, porphyrine derivatives, phthalocyanine derivatives,naphthalocyanine derivatives, alkali metal complexes, and alkalineearth-based complexes. The carbocyclic compound, the heterocycliccompound, and the amine-based compound may be optionally substitutedwith a substituent containing at least one element selected from O, N,S, Se, Si, F, Cl, Br, and I. In one embodiment, at least one selectedfrom the first capping layer 210 and the second capping layer 220 mayeach independently include an amine-based compound.

In one embodiment, at least one selected from the first capping layer210 and the second capping layer 220 may each independently include thecompound represented by Formula 201 or the compound represented byFormula 202.

In embodiments, at least one selected from the first capping layer 210and the second capping layer 220 may each independently include acompound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5below, but embodiments are not limited thereto.

Hereinbefore, the organic light-emitting device according to anembodiment has been described in connection with FIGS. 1 to 4, butembodiments are not limited thereto.

Layers constituting the hole transport region, an emission layer, andlayers constituting the electron transport region may be formed in acertain region by using one or more suitable methods selected fromvacuum deposition, spin coating, casting, Langmuir-Blodgett (LB)deposition, ink-jet printing, laser-printing, and laser-induced thermalimaging (LITI).

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed byvacuum deposition, the deposition may be performed at a depositiontemperature of about 100° C. to about 500° C., a vacuum degree of about10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/secto about 100 Å/sec by taking into account a material to be included in alayer to be formed, and the structure of a layer to be formed.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed by spincoating, the spin coating may be performed at a coating speed of about2,000 rpm to about 5,000 rpm and at a heat treatment temperature ofabout 80° C. to about 200° C. by taking into account a material to beincluded in a layer to be formed, and the structure of a layer to beformed.

Definitions of Substituents

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched aliphatic saturated hydrocarbon monovalent group having 1 to 60carbon atoms, and examples thereof include a methyl group, an ethylgroup, a propyl group, an isobutyl group, a sec-butyl group, atert-butyl group, a pentyl group, an isoamyl group, and a hexyl group.The term “C₁-C₆₀ alkylene group” as used herein refers to a divalentgroup having the same structure as that of the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon double bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group, and examples thereof include anethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀alkenylene group” as used herein refers to a divalent group having thesame structure as that of the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon triple bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group, and examples thereof include anethynyl group, and a propynyl group. The term “C₂-C₆₀ alkynylene group”as used herein refers to a divalent group having the same structure asthat of the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by -OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, andexamples thereof include a cyclopropyl group, a cyclobutyl group, acyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term“C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent grouphaving the same structure as that of the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent monocyclic group having at least one heteroatom selected fromN, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, andexamples thereof include a 1,2,3,4-oxatriazolidinyl group, atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalentgroup having the same structure as that of the C₁-C₁₀ heterocycloalkylgroup.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic group that has 3 to 10 carbon atoms and at leastone carbon-carbon double bond in the ring thereof and no aromaticity,and examples thereof include a cyclopentenyl group, a cyclohexenylgroup, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group that has at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one carbon-carbon double bond in its ring. Examples of theC₁-C₁₀ heterocycloalkenyl group include a4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, anda 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as that of the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, and aC₆-C₆₀ arylene group used herein refers to a divalent group having acarbocyclic aromatic system having 6 to 60 carbon atoms. Examples of theC₆-C₆₀ aryl group include a phenyl group, a naphthyl group, ananthracenyl group, a phenanthrenyl group, a pyrenyl group, and achrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene groupeach include two or more rings, the rings may be fused to each other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a carbocyclic aromatic system that has at least oneheteroatom selected from N, O, Si, P, and S as a ring-forming atom, inaddition to 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group”as used herein refers to a divalent group having a carbocyclic aromaticsystem that has at least one heteroatom selected from N, O, Si, P, and Sas a ring-forming atom, in addition to 1 to 60 carbon atoms. Examples ofthe C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinylgroup, a pyrazinyl group, a pyridazinyl group, a triazinyl group, aquinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroarylgroup and the C₁-C₆₀ heteroarylene group each include two or more rings,the rings may be condensed with each other.

The term “C₆-C₆₀ aryloxy group” as used herein refers to -OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group” asused herein refers to -SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed with each other, only carbonatoms as ring-forming atoms, and no aromaticity in its entire molecularstructure. A detailed example of the monovalent non-aromatic condensedpolycyclic group is a fluorenyl group. The term “divalent non-aromaticcondensed polycyclic group” as used herein refers to a divalent grouphaving the same structure as that of the monovalent non-aromaticcondensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group (for example, having 1 to 60carbon atoms) having two or more rings condensed to each other, at leastone heteroatom selected from N, O, Si, P, and S, other than carbonatoms, as a ring-forming atom, and no aromaticity in its entiremolecular structure. An example of the monovalent non-aromatic condensedheteropolycyclic group is a carbazolyl group. The term “divalentnon-aromatic condensed heteropolycyclic group” as used herein refers toa divalent group having the same structure as that of the monovalentnon-aromatic condensed heteropolycyclic group.

The term “C₅-C₆₀ carbocyclic group” as used herein refers to amonocyclic or polycyclic group having 5 to 60 carbon atoms in which aring-forming atom is a carbon atom only. The term “C₅-C₆₀ carbocyclicgroup” as used herein refers to an aromatic carbocyclic group or anon-aromatic carbocyclic group. The C₅-C₆₀ carbocyclic group may be aring, such as benzene, a monovalent group, such as a phenyl group, or adivalent group, such as a phenylene group. In embodiments, depending onthe number of substituents connected to the C₅-C₆₀ carbocyclic group,the C₅-C₆₀ carbocyclic group may be a trivalent group or a quadrivalentgroup.

The term “C₁-C₆₀ heterocyclic group” as used herein refers to a grouphaving the same structure as the C₅-C₆₀ carbocyclic group, except thatas a ring-forming atom, at least one heteroatom selected from N, O, Si,P, and S is used in addition to carbon (the number of carbon atoms maybe in a range of 1 to 60).

In the specification, at least one substituent of the substituted C₅-C₆₀carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, thesubstituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group,the substituted C₁-C₁₀ heterocycloalkenylene group, the substitutedC₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, thesubstituted divalent non-aromatic condensed polycyclic group, thesubstituted divalent non-aromatic condensed heteropolycyclic group, thesubstituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group,the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxygroup, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group may be selectedfrom:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃),—N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and—P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently beselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aheterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, amonovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.

The term “Ph” as used herein refers to a phenyl group, the term “Me” asused herein refers to a methyl group, the term “Et” as used hereinrefers to an ethyl group, the term “ter-Bu” or “t-Bu” or “But” as usedherein refers to a tert-butyl group, and the term “OMe” as used hereinrefers to a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl groupsubstituted with a phenyl group”. In other words, the “biphenyl group”is a substituted phenyl group having a C₆-C₆₀ aryl group as asubstituent.

The term “terphenyl group” as used herein refers to “a phenyl groupsubstituted with a biphenyl group”. In other words, the “terphenylgroup” is a phenyl group having, as a substituent, a C₆-C₆₀ aryl groupsubstituted with a C₆-C₆₀ aryl group.

* and *′ as used herein, unless defined otherwise, each refer to abinding site to a neighboring atom in a corresponding formula.

Hereinafter, a compound according to embodiments and an organiclight-emitting device according to embodiments will be described indetail with reference to Synthesis Examples and Examples. The wording “Bwas used instead of A” used in describing Synthesis Examples refers towhere an identical molar equivalent of B was used in place of A.

EXAMPLES Synthesis Example 1: Synthesis of Compound 27

Synthesis of Intermediate 27-1

1,3-dibromo-5-phenoxybenzene (1 eq), diphenylamine (0.9 eq),tris(dibenzylideneacetone)dipalladium (0) (0.05 eq), BINAP (0.1 eq), andsodium tert-butoxide (3 eq) were dissolved in toluene, and stirred, inthe nitrogen atmosphere, at a temperature of 100° C. for 12 hours. Aftercooling, the organic layer obtained by washing three times with ethylacetate and water, was dried using MgSO₄ and dried under reducedpressure. Subsequently, the purification process was performed by columnchromatography to obtain Intermediate 27-1. (Yield: 65%).

Synthesis of Intermediate 27-2

Intermediate 27-1 (1 eq), aniline (1.5 eq),tris(dibenzylideneacetone)dipalladium(0) (0.05 eq),tri-tert-butylphosphine (0.1 eq), and sodium tert-butoxide (3 eq) weredissolved in toluene, and stirred, in the nitrogen atmosphere, at atemperature of 100° C. for 12 hours. After cooling, the organic layerobtained by washing three times with ethyl acetate and water, was driedusing MgSO₄ and dried under reduced pressure. Subsequently, thepurification process was performed by column chromatography to obtainIntermediate 27-2. (Yield: 85%)

Synthesis of Intermediate 27-3

Intermediate 27-3 was obtained in the same manner as used to synthesizeIntermediate 27-2, except that5-chloro-N¹,N¹,N³,N³-tetraphenylbenzene-1,3-diamine (1 eq) was usedinstead of Intermediate 27-1. (Yield: 79%).

Synthesis of Intermediate 27-4

Intermediate 27-3 (1 eq), 1,3-dibromobenzene (1.5 eq),tris(dibenzylideneacetone)dipalladium(0) (0.05 eq), BINAP (0.1 eq), andsodium tert-butoxide (3 eq) were dissolved in toluene, and stirred, inthe nitrogen atmosphere, at a temperature of 100° C. for 12 hours. Aftercooling, the organic layer obtained by washing three times with ethylacetate and water, was dried using MgSO₄ and dried under reducedpressure. Subsequently, the purification process was performed by columnchromatography to obtain Intermediate 27-4. (Yield: 58%)

Synthesis of Intermediate 27-5

Intermediate 27-2 (1 eq), Intermediate 27-4 (1 eq),tris(dibenzylideneacetone)dipalladium(0) (0.05 eq),tri-tert-butylphosphine (0.1 eq), and sodium tert-butoxide (3 eq) weredissolved in toluene, and stirred, in the nitrogen atmosphere, at atemperature of 100° C. for 12 hours. After cooling, the organic layerobtained by washing three times with ethyl acetate and water, was driedusing MgSO₄ and dried under reduced pressure. Subsequently, thepurification process was performed by column chromatography to obtainIntermediate 27-5. (Yield: 73%).

Synthesis of Compound 27

Intermediate 27-5 (1 eq) and triphenylborane (2 eq) were dissolved inortho dichlorobenzene, and a flask was cooled in the nitrogen atmosphereat a temperature of 0° C. and Bl₃ (5 eq) was slowly added thereto. Aftercompletion of adding dropwise, the temperature was raised to 180° C. andthe resultant mixture was stirred for 12 hours. After cooling,triethylamine was slowly added dropwise to the flask to terminate thereaction until the exotherm stopped, and a hexane was added thereto tocause precipitation and a solid was obtained therefrom by filtration.The obtained solid was purified by silica filtration and then purifiedby MC/Hex (CH₂Cl₂/hexane) recrystallization to obtain Compound 27.(Yield: 14%)

Synthesis Examples 2 and 3: Synthesis of Compounds 28 and 29

Synthesis of Intermediate 28-1

3,5-bis(diphenylamino)phenol (1 eq), 1-bromo-3-fluorobenzene (1.5 eq),and K₃PO₄ (2 eq) were dissolved in DMF, and stirred at a temperature of160° C. for 12 hours. After cooling, the solvent was removed therefromunder reduced pressure, and the resultant product was washed three timeswith dichloromethane and water, and the organic layer obtained byseparation was dried using MgSO₄ and dried under reduced pressure.Subsequently, the separation-purification process was performed bycolumn chromatography to obtain Intermediate 28-1. (Yield: 65%).

Synthesis of Intermediate 28-2

Intermediate 28-2 was obtained in the same manner as used to synthesizeIntermediate 27-5, except that Intermediate 28-1 and Intermediate 27-3were used instead of Intermediate 27-4 and Intermediate 27-2,respectively. (Yield: 77%).

Synthesis of Compounds 28 and 29

After synthesized in the same manner as used to prepare Compound 27using Intermediate 28-2, Compounds 28 and 29 were obtained by separationthrough column chromatography. (Yield of Compound 28: 6%, and Compound29: 7%)

Synthesis Example 4: Synthesis of Compound 31

Synthesis of Intermediate 31-1

N¹,N³-diphenylbenzene-1,3-diamine (1 eq),5-chloro-N¹,N¹,N³,N³-tetraphenylbenzene-1,3-diamine (2.5 eq),tris(dibenzylideneacetone)dipalladium (0) (0.05 eq),tri-tert-butylphosphine (0.1 eq), and sodium tert-butoxide (3 eq) weredissolved in toluene, and stirred, in the nitrogen atmosphere, at atemperature of 100° C. for 12 hours. After cooling, the organic layerobtained by washing three times with ethyl acetate and water, was driedusing MgSO₄ and dried under reduced pressure. Subsequently, theseparation-purification process was performed by column chromatographyto obtain Intermediate 31-1. (Yield: 60%).

Synthesis of Compound 31

Compound 31 was synthesized in the same manner as used to synthesizeCompound 27, except that Intermediate 31-1 was used instead ofIntermediate 27-5. (Yield: 19%)

Synthesis Example 5: Synthesis of Compound 17

Synthesis of Intermediate 17-1

Intermediate 27-4 (1 eq), 3-(diphenylamino)-5-phenoxyphenol (1 eq), CuI(0.1 eq), 1,10-Phen. (0.1 eq), and K₃PO₄ (3 eq) were dissolved in DMF,and stirred at a temperature of 160° C. for 24 hours. After cooling, thesolvent was removed therefrom under reduced pressure, and the resultantproduct was washed three times with dichloromethane and water, and theorganic layer obtained by separation was dried using MgSO₄ and driedunder reduced pressure. Subsequently, the separation-purificationprocess was performed by column chromatography to obtain Intermediate17-1. (Yield: 55%)

Synthesis of Compound 17

Compound 17 was synthesized in the same manner as used to synthesizeCompound 27, except that Intermediate 17-1 was used instead ofIntermediate 27-5. (Yield: 12%)

Synthesis Example 6: Synthesis of Compound 18

Synthesis of Intermediate 18-1

Intermediate 18-1 was synthesized using Intermediate 27-2 andIntermediate 28-1 in the same manner as used to synthesize Intermediate27-5. (Yield: 68%).

Synthesis of Compound 18

Compound 18 was synthesized in the same manner as used to synthesizeCompound 27, except that Intermediate 18-1 was used instead ofIntermediate 27-5. (Yield: 9%)

Synthesis Example 7: Synthesis of Compound 20

Synthesis of Intermediate 20-1

Intermediate 20-1 was synthesized in the same manner as used tosynthesize Intermediate 17-1, except that 1,3-dibromobenzene (1 eq) and3,5-bis(diphenylamino)phenol (2 eq) were used instead of Intermediate27-4 and 3-(diphenylamino)-5-phenoxyphenol, respectively. (Yield: 48%)

Synthesis of Compound 20

Compound 20 was synthesized in the same manner as used to synthesizeCompound 27, except that Intermediate 20-1 was used instead ofIntermediate 27-5. (Yield: 14%)

Synthesis Example 8: Synthesis of Compound 7

Synthesis of Intermediate 7-1

Intermediate 7-1 was synthesized in the same manner as used tosynthesize Intermediate 17-1, except that Intermediate 28-1 (1 eq) and3,5-bis(diphenylamino)phenol (1 eq) were used instead of Intermediate27-4 and 3-(diphenylamino)-5-phenoxyphenol, respectively. (Yield: 56%)

Synthesis of Compound 7

Compound 7 was synthesized in the same manner as used to synthesizeCompound 27, except that Intermediate 7-1 was used instead ofIntermediate 27-5. (Yield: 5%)

¹H NMR and MS/FAB of the compounds synthesized according to SynthesisExamples 1 to 8 are shown in Table 1 below.

Synthesis methods of compounds other than Compounds shown in Table 1 mayalso be easily recognized by those of ordinary skill in the art byreferring to the synthesis mechanisms and source materials describedabove.

TABLE 1 MS/FAB Compound ¹H NMR (CDCl₃, 400 MHz) found calc. 27 10.46(1H, s); 9.41-9.37 (1H, m), 1029.58 1029.6 9.34-9.30 (3H, m) 7.51-7.36(13H, m), 7.23-7.15 (10H, m), 7.09-6.86 (14H, m) 5.92-5.78 (4H, m) 2810.51 (1H, s); 9.36-9.30 (4H, m), 1029.58 1029.6 7.52-7.37 (18H, m)7.24-7.15 (7H, m), 7.06-6.84 (12H, m), 5.90-5.75 (4H, m) 29 10.52 (1H,s); 9.40-9.32 (4H, m), 1029.59 1029.6 7.49-7.31 (18H, m), 7.23-7.15 (7H,m), 7.09-6.82 (12H, m), 5.90-5.73 (4H, m) 31 10.5 (1H, s), 9.33-9.29(4H, m), 1104.70 1104.71 7.48-7.30 (18H, m) 7.18-7.10 (10H, m),7.09-6.92 (14H, m), 5.99-5.85 (4H, m) 17 10.53 (1H, s), 9.45-9.40 (1H,m), 954.48 954.49 9.37-9.31 (3H, m) 7.63-7.40 (13H, m), 7.24-7.15 (7H,m), 7.13-6.87 (12H, m) 5.99-5.80 (4H, m) 18 10.52 (1H, s), 9.41-9.37(2H, m), 954.47 954.49 9.34-9.30 (2H, m) 7.62-7.46 (13H, m), 7.23-7.13(7H, m), 7.11-6.84 (12H, m) 6.01-5.79 (4H, m) 20 10.57 (1H, s),9.50-9.43 (2H, m), 954.48 954.49 9.36-9.31 (2H, m) 7.64-7.43 (18H, m),7.24-7.17 (4H, m), 7.15-6.86 (10H, m) 6.09-5.86 (4H, m) 7 10.53 (1H, s),9.60-9.54 (1H, m), 879.37 879.38 9.51-9.45 (1H, m), 9.39-9.34 (2H, m),7.65-7.40 (13H, m), 7.23-7.16 (4H, m), 7.13-6.89 (10H, m), 9.07-5.89(4H, m)

EVALUATION EXAMPLE Evaluation Example 1: Evaluation of Properties ofTADF Compound

For the compounds synthesized according to Synthesis Examples 1 to 4,compound DABNA-1 and Compounds A to C, HOMO energy levels, LUMO energylevels, energy gap (E_(g)), T1, S1 and oscillator strength werecalculated by simulation according to the density functional theory(DFT) method based on B3LYP using Gaussian 09 program.

TABLE 2 HOMO LUMO E_(g) T1 S1 Oscillator No. (eV) (eV) (eV) (eV) (eV)strength ΔE_(ST) 27 −5.04 −1.68 3.36 2.61 2.89 0.74 0.29 28 −5.03 −1.663.37 2.62 2.90 0.827 0.29 29 −5.01 −1.69 3.32 2.55 2.85 0.746 0.30 31−4.89 −1.55 3.34 2.56 2.86 0.757 0.30 DABNA−1 −4.73 −1.09 3.64 2.62 3.110.204 0.49 A −4.83 −1.94 2.89 1.95 2.37 0.153 0.42 B −4.93 −1.75 3.182.39 2.70 0.55 0.31 C −5.12 −1.49 3.63 2.69 3.08 0.054 0.39

From the results of the Table 1, it can be seen that the compoundaccording to the embodiment has a low ΔE_(ST) and an increased f value,compared to the known compounds DABNA-1 and Compounds A to C.

Example 1

As an anode, a glass substrate with 15 Ωcm² (1,200 Å) ITO thereon, whichwas manufactured by Corning Inc., was cut to a size of 50 mm×50 mm×0.7mm, and the glass substrate was sonicated by using isopropyl alcohol andpure water for 5 minutes each, and then ultraviolet (UV) light wasirradiated for 30 minutes thereto and ozone was exposed thereto forcleaning. The resultant glass substrate was loaded onto a vacuumdeposition apparatus. NPD was vacuum-deposited on the substrate to forma hole injection layer having a thickness of 300 Å, and as a holetransport compound, TCTA was vacuum-deposited thereon to form a firsthole transport layer having a thickness of 200 Å. CzSi wasvacuum-deposited on the first hole transport layer to form a second holetransport layer having a thickness of 100 Å.

mCP and Compound 27 were co-deposited at the weight ratio of 99:1 on thesecond hole transport layer to form an emission layer having a thicknessof 200 Å. TSPO1 was deposited on the emission layer to form a bufferlayer having a thickness of 200 Å, and TPBI was deposited on the bufferlayer to form an electron transport layer having a thickness of 300 Å toform an electron transport layer. LiF, which is a halogenated alkalinemetal, was deposited on the electron transport layer having a thicknessof 10 Å, and Al was vacuum deposited to form a cathode having athickness of 3000 Å to form an LiF/Al electrode, thereby completing themanufacture of an organic light-emitting device.

Examples 2 and 8

Organic light-emitting devices were manufactured in the same manner asin Example 1, except that the compounds of Table 3 were used to formemission layers.

Comparative Examples 1 to 4

Organic light-emitting devices were manufactured in the same manner asin Example 1, except that Compound DABNA-1 and Compounds A to C wereused to form emission layers.

The driving voltage (V) at a current density of 10 mA/cm², efficiency(cd/A), and maximum quantum efficiency (%) of the organic light-emittingdevices manufactured according to Examples 1 to 8 and ComparativeExamples 1 to 4 were measured. The results thereof are shown in Table 3.The driving voltage and current density of an organic light-emittingdevice were measured using a source meter (Keithley Instrument, 2400series), and the maximum quantum efficiency was measured using theexternal quantum efficiency measurement device C9920-2-12 of HamamatsuPhotonics Inc.

TABLE 3 Maximum Driving quantum Luminescent voltage Efficiencyefficiency Emission material (V) (cd/A) (%) color Example 1 Compound 4.624.7 24.1 Blue 27 Example 2 Compound 4.7 23.8 21.8 Blue 28 Example 3Compound 4.7 24.1 22.2 Blue 29 Example 4 Compound 4.6 25.2 23.8 Blue 31Example 5 Compound 4.9 23.4 21.6 Blue 17 Example 6 Compound 4.9 22.421.4 Blue 18 Example 7 Compound 4.7 22.7 20.8 Blue 20 Example 8 Compound4.5 21.7 20.4 Blue 7 Comparative DABNA-1 5.6 19.4 19.1 Blue Example 1Comparative Compound 5.7 20.1 15.9 Greenish Example 2 A blue ComparativeCompound 6.1 19.8 18.2 Bluish Example 3 B green Comparative Compound 5.421.6 20.5 Blue Example 4 C

From the results of the Table 3, it can be seen that the organiclight-emitting devices of Examples 1 to 8 using the compound accordingto one embodiment as the dopant of an emission layer have lower drivingvoltage, higher current efficiency, and higher maximum quantumefficiency than the organic light-emitting devices of ComparativeExamples 1 to 4. It can be seen that the organic light-emitting devicesof Examples 1 to 8 emits blue light having high color purity compared tothe organic light-emitting devices of Comparative Example 1 to 4.

For example, when the compound according to the disclosure is used in anelectronic apparatus, such as an organic light-emitting device, anexcellent effect can be obtained in terms of driving voltage andefficiency.

The organic light-emitting device including the condensed cycliccompound may have a low driving voltage, high efficiency, and a longlifespan.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. While the embodiments have beendescribed with reference to the figures, it will be understood by thoseof ordinary skill in the art that various changes in form and detailsmay be made therein without departing from the spirit and scope asdefined by the following claims.

What is claimed is:
 1. An organic light-emitting device comprising: afirst electrode; a second electrode facing the first electrode; and anorganic layer disposed between the first electrode and the secondelectrode and comprising an emission layer; wherein the organiclight-emitting device comprises a condensed cyclic compound representedby Formula 1:

(L₂₁)_(a21)-(Ar₂₁)_(b21)  <Formula 2> wherein in Formula 1 and Formula2, B is boron, ring A₁ to ring A₅ are each independently selected from abenzene ring, a naphthalene ring, a pyridine ring, a pyrimidine ring, apyridazine ring, and a pyrazine ring, Z₁ is C(R₁) or N, Z₂ is C(R₂) orN, Z₃ is C(R₃) or N, X₁ to X₄ are each independently selected fromC(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), N(R₁₁), O, and S, L₂₁ is a substituted orunsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstitutedC₁-C₆₀ heterocyclic group, a21 is an integer from 0 to 3, Ar₂₁ isselected from a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group,a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and —N(R₁₃)(R₁₄), b21 is an integer from 1 to 5, R₁ to R₈ are eachindependently selected from a group represented by Formula 2, hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an am idino group, a hydrazine group, a hydrazone group, acarboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, aphosphoric acid or a salt thereof, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —S(═O)₂(C₂₁), and —P(═O)(Q₁)(Q₂), R₁₁ to R₁₄ are eachindependently selected from a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₆-C₆₀ aryl group, a substitutedor unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,with the proviso that: when at least one of X₁ to X₄ is selected fromC(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), and N(R₁₁), at least one pair of substituentsare optionally linked, via a single bond or a linking group, to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, the pair of substituentsselected from the group consisting of R₁₁ and R₁₂, ring A₁ and R₁₁, ringA₄ and R₁₁, ring A₅ and R₁₁, ring A₆ and R₁₁, and ring A₇ and R₁₁, c4 toc8 are each independently an integer from 0 to 6, at least onesubstituent of the substituted C₅-C₆₀ carbocyclic group, the substitutedC₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, thesubstituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group,the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, anda C₁-C₆₀ alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃),—N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and—P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, and a monovalent non-aromatic condensed heteropolycyclic group; aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl groupsubstituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substitutedwith a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, a biphenyl group, and a terphenylgroup, and * indicates a binding site to a neighboring atom.
 2. Theorganic light-emitting device of claim 1, wherein the first electrode isan anode, the second electrode is a cathode, the organic layercomprises: the condensed cyclic compound; a hole transport regiondisposed between the first electrode and the emission layer; and anelectron transport region disposed between the emission layer and thesecond electrode, the hole transport region comprises a hole injectionlayer, a hole transport layer, an emission auxiliary layer, an electronblocking layer, or any combination thereof, and the electron transportregion comprises a buffer layer, a hole blocking layer, an electrontransport layer, an electron injection layer, or any combinationthereof.
 3. The organic light-emitting device of claim 1, wherein theemission layer comprises the condensed cyclic compound.
 4. The organiclight-emitting device of claim 3, wherein the condensed cyclic compoundincluded in the emission layer is a thermally activated delayedfluorescence emitter (TADF emitter), and the emission layer emitsdelayed fluorescence.
 5. The organic light-emitting device of claim 3,wherein the emission layer further comprises a host, the condensedcyclic compound included in the emission layer is a dopant, and anamount of the host included in the emission layer is greater than anamount of the condensed cyclic compound included in the emission layer.6. The organic light-emitting device of claim 5, wherein the hostincludes an anthracene compound, a carbazole compound, a benzimidazolecompound, a phosphine oxide compound, an arylamine compound, astyrylamine compound, or any combination thereof.
 7. The organiclight-emitting device of claim 1, wherein the emission layer is a firstemission layer that emits first light, the organic light-emitting devicefurther comprises between the first electrode and the second electrode:a second emission layer that emits second light, or a second emissionlayer that emits second light and a third emission layer that emitsthird light, and the first light and the second light are emitted asmixed light, or the first light, the second light, and the third lightare emitted as mixed light.
 8. A condensed cyclic compound representedby Formula 1:

*-(L₂₁)_(a21)(Ar₂₁)_(b21)  <Formula 2> wherein in Formula 1 and Formula2, B is boron, ring A₁ to ring A₅ are each independently selected from abenzene ring, a naphthalene ring, a pyridine ring, a pyrimidine ring, apyridazine ring, and a pyrazine ring, Z₁ is C(R₁) or N, Z₂ is C(R₂) orN, Z₃ is C(R₃) or N, X₁ to X₄ are each independently selected fromC(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), N(R₁₁), O, and S, L₂₁ is a substituted orunsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstitutedC₁-C₆₀ heterocyclic group, a21 is an integer from 0 to 3, Ar₂₁ isselected from a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group,a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and —N(R₁₃)(R₁₄), b21 is an integer from 1 to 5, R₁ to R₈ are eachindependently selected from a group represented by Formula 2, hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an am idino group, a hydrazine group, a hydrazone group, acarboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, aphosphoric acid or a salt thereof, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —S(═O)₂(C₂₁), and —P(═O)(Q₁)(Q₂), R₁₁ to R₁₄ are eachindependently selected from a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₆-C₆₀ aryl group, a substitutedor unsubstituted heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,with the proviso that: when at least one of X₁ to X₄ is selected fromC(R₁₁)(R₁₂), Si(R₁₁)(R₁₂), and N(R₁₁), at least one pair of substituentsare optionally linked via a single bond or a linking group to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, the pair of substituentsselected from the group consisting of R₁₁ and R₁₂, ring A₁ and R₁₁, ringA₄ and R₁₁, ring A₅ and R₁₁, ring A₆ and R₁₁, and ring A₇ and R₁₁, c4 toc8 are each independently an integer from 0 to 6, at least onesubstituent of the substituted C₅-C₆₀ carbocyclic group, the substitutedC₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, thesubstituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group,the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, anda C₁-C₆₀ alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃),—N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and—P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, and a monovalent non-aromatic condensed heteropolycyclic group; aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl groupsubstituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substitutedwith a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, a biphenyl group, and a terphenylgroup, and * indicates a binding site to a neighboring atom.
 9. Thecondensed cyclic compound of claim 8, wherein ring A₁ to ring A₅ areeach independently selected from a benzene ring, a naphthalene ring, anda pyridine ring.
 10. The condensed cyclic compound of claim 8, whereini) X₁ to X₄ are each O or S, ii) one of X₁ to X₄ is N(R₁₁), and theothers are O or S, iii) two of X₁ to X₄ are N(R₁₁), and the others are Oor S, iv) three of X₁ to X₄ are N(R₁₁), and the other is O or S, or v)X₁ to X₄ are each N(R₁₁).
 11. The condensed cyclic compound of claim 8,wherein Ar₂₁ is selected from a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenylgroup, a pentalenyl group, an indenyl group, a naphthyl group, anazulenyl group, a heptalenyl group, an indacenyl group, an acenaphthylgroup, a fluorenyl group, a spiro-bifluorenyl group, aspiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, aspiro-fluorene-benzofluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoxazolyl group, a benzimidazolyl group, afuranyl group, a benzofuranyl group, a thiophenyl group, abenzothiophenyl group, a thiazolyl group, an isothiazolyl group, abenzothiazolyl group, an isoxazolyl group, an oxazolyl group, atriazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a benzoxazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a phenoxazinyl group, a phenothiazinyl group, a9,9-dihydroan acridinyl group, a 1,2,3,4-tetrahydroquinolinyl group, anda piperidinyl group; a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenylgroup, a pentalenyl group, an indenyl group, a naphthyl group, anazulenyl group, a heptalenyl group, an indacenyl group, an acenaphthylgroup, a fluorenyl group, a spiro-bifluorenyl group, aspiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, aspiro-fluorene-benzofluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoxazolyl group, a benzimidazolyl group, afuranyl group, a benzofuranyl group, a thiophenyl group, abenzothiophenyl group, a thiazolyl group, an isothiazolyl group, abenzothiazolyl group, an isoxazolyl group, an oxazolyl group, atriazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a benzoxazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a phenoxazinyl group, a phenothiazinyl group, a9,9-dihydroan acridinyl group, a 1,2,3,4-tetrahydroquinolinyl group, anda piperidinyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group,an azulenyl group, a heptalenyl group, an indacenyl group, anacenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, aspiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, aspiro-fluorene-benzofluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoxazolyl group, a benzimidazolyl group, afuranyl group, a benzofuranyl group, a thiophenyl group, abenzothiophenyl group, a thiazolyl group, an isothiazolyl group, abenzothiazolyl group, an isoxazolyl group, an oxazolyl group, atriazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a benzoxazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a phenoxazinyl group, a phenothiazinyl group, a9,9-dihydroan acridinyl group, a 1,2,3,4-tetrahydroquinolinyl group, apiperidinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂);and —N(R₁₃)(R₁₄), wherein Q₃₁ to Q₃₃ are each independently selectedfrom hydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₆-C₂₀ aryl group, a C₆-C₂₀ aryl groupsubstituted with a C₁-C₂₀ alkyl group, a C₆-C₂₀ aryl group substitutedwith a C₆-C₂₀ aryl group, a C₁-C₂₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, and a terphenyl group.
 12. Thecondensed cyclic compound of claim 8, wherein Ar₂₁ is selected from agroup represented by one of Formulae 5-1 to 5-19 and —N(R₁₃)(R₁₄):

wherein in Formulae 5-1 to 5-19, Y₃₁ is O, S, C(Z₃₃)(Z₃₄), N(Z₃₅), orSi(Z₃₆)(Z₃₇), W₃₁ is O, S, or C(Z₃₈)(Z₃₉), Z₃₁ to Z₃₉ are eachindependently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazine group, a hydrazone group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptylgroup, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, abiphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenylgroup, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a quinolinylgroup, an isoquinolinyl group, a benzoquinolinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a dibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃),—N(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), e2 is selected from 1 and 2, e3 is aninteger from 1 to 3, e4 is an integer from 1 to 4, e6 is an integer from1 to 6, e7 is an integer from 1 to 5, e8 is an integer from 1 to 8, Q₃₁to Q₃₃ are each independently selected from hydrogen, deuterium, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, aC₆-C₂₀ aryl group, a C₆-C₂₀ aryl group substituted with a C₁-C₂₀ alkylgroup, a C₆-C₂₀ aryl group substituted with a C₆-C₂₀ aryl group, aC₁-C₂₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group, and aterphenyl group, and * indicates a binding site to a neighboring atom.13. The condensed cyclic compound of claim 8, wherein Ar₂₁ is a grouprepresented by one of Formulae 6-1 to 6-13:

wherein in Formulae 6-1 to 6-13, t-Bu is a tert-butyl group, Ph is aphenyl group, and * indicates a binding site to a neighboring atom. 14.The condensed cyclic compound of claim 8, wherein R₁ to R₈ are eachindependently selected from a group represented by Formula 2, hydrogen,deuterium, —F, —Cl, —Br, —I, a cyano group, a C₁-C₂₀ alkyl group, and aC₁-C₂₀ alkoxy group; and a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group,each substituted with at least one selected from deuterium, —F, —Cl,—Br, —I, a cyano group, a phenyl group, and a biphenyl group.
 15. Thecondensed cyclic compound of claim 8, wherein R₁ to R₈ are eachhydrogen, or at least one of R₁ to R₈ is a group represented by Formula2, and the others, which are not the group represented by Formula 2, arehydrogen.
 16. The condensed cyclic compound of claim 8, wherein R₁₁ toR₁₄ are each independently selected from: a C₁-C₂₀ alkyl group; a C₁-C₂₀alkyl group substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a phenyl group, and abiphenyl group; a cyclopentyl group, a cyclohexyl group, a cycloheptylgroup, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, aspiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, aspiro-fluorene-benzofluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoxazolyl group, a benzimidazolyl group, afuranyl group, a benzofuranyl group, a thiophenyl group, abenzothiophenyl group, a thiazolyl group, an isothiazolyl group, abenzothiazolyl group, an isoxazolyl group, an oxazolyl group, atriazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a benzoxazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, and adibenzosilolyl group; and a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenylgroup, a pentalenyl group, an indenyl group, a naphthyl group, anazulenyl group, a heptalenyl group, an indacenyl group, an acenaphthylgroup, a fluorenyl group, a spiro-bifluorenyl group, aspiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, aspiro-fluorene-benzofluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoxazolyl group, a benzimidazolyl group, afuranyl group, a benzofuranyl group, a thiophenyl group, abenzothiophenyl group, a thiazolyl group, an isothiazolyl group, abenzothiazolyl group, an isoxazolyl group, an oxazolyl group, atriazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a benzoxazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, and adibenzosilolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group,an azulenyl group, a heptalenyl group, an indacenyl group, anacenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, aspiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, aspiro-fluorene-benzofluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoxazolyl group, a benzimidazolyl group, afuranyl group, a benzofuranyl group, a thiophenyl group, abenzothiophenyl group, a thiazolyl group, an isothiazolyl group, abenzothiazolyl group, an isoxazolyl group, an oxazolyl group, atriazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a benzoxazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and—B(Q₃₁)(Q₃₂), wherein Q₃₁ to Q₃₃ are each independently selected fromhydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₆-C₂₀ aryl group, a C₆-C₂₀ aryl groupsubstituted with a C₁-C₂₀ alkyl group, a C₆-C₂₀ aryl group substitutedwith a C₆-C₂₀ aryl group, a C₁-C₂₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, and a terphenyl group.
 17. Thecondensed cyclic compound of claim 8, wherein the condensed cycliccompound is represented by Formula 1-1:

wherein in Formula 1-1, X₁ to X₄ and R₁ to R₃ are the same as describedin connection with Formula 1, R₄₁ to R₄₄ are the same as described inconnection with R₄ in Formula 1, R₅₁ to R₅₄ are the same as described inconnection with R₅ in Formula 1, R₆₁ to R₆₄ are the same as described inconnection with R₆ in Formula 1, R₇₁ to R₇₄ are the same as described inconnection with R₇ in Formula 1, and R₈₁ to R₈₃ are the same asdescribed in connection with R₈ in Formula
 1. 18. The condensed cycliccompound of claim 17, wherein wherein in Formula 1-1, i) R₄₁ to R₄₄, R₅₁to R₅₄, R₆₁ to R₆₄, Rn to R₇₄, and R₈₁ to R₈₃ are each hydrogen, or ii)at least one of R₄₂ and R₈₂ is a group represented by Formula 2, andR₄₁, R₄₃, R₄₄, R₅₁ to R₅₄, R₆₁ to R₆₄, R₇₁ to R₇₄, R₈₁, and R₈₃ are eachhydrogen.
 19. The condensed cyclic compound of claim 8, wherein thecondensed cyclic compound is represented by one of Formulae 1-1A to1-1F:

wherein in Formulae 1-1A to 1-1F, X₁ to X₄ and R₁ to R₃ are the same asdescribed in connection with Formula 1, R₄₁ to R₄₄ are the same asdescribed in connection with R₄ in Formula 1, R₅₁ to R₅₄ are the same asdescribed in connection with R₅ in Formula 1, R₆₁ to R₆₄ are the same asdescribed in connection with R₆ in Formula 1, R₇₁ to R₇₄ are the same asdescribed in connection with R₇ in Formula 1, R₈₁ to R₈₃ are the same asdescribed in connection with R₈ in Formula 1, and R₁₁₁ to R₁₁₄ are thesame as described in connection with R₁ in Formula
 1. 20. The condensedcyclic compound of claim 8, wherein the condensed cyclic compound isselected from Compounds 1 to 37: